Figure legends:
Figure 1: The initial electrocardiographic (ECG) shows atrial fibrillation.
Figure 2: LASSO mapping showed there was no potential activity in the left upper pulmonary vein, the left atrium and left atrial appendage (A,B and C). A small amount of potential activity was recorded in the left lower pulmonary vein (D).
Figure 3: Ablation electrode show part of right atrium without potential. Atrial flutter stopped andĀ converted to sinus rhythm during the process of tricuspid isthmus linear ablation.
Figure 4: A,B: Pericardial effusion, peak A can be seen in the blood flow spectrum of the mitral valve orifice during diastole, showing left atrial had contraction on July 10th. C,D: Significant thickening of the wall of left atrial on August 3th, no Peak A was found in the blood flow spectrum of the mitral valve orifice during diastole, indicating left atrial had no contraction.